There are 2 more specs, not just affliction.
Yes locks didn't move and cast before, but game was different before also. They had much much better survivability and could just stand there and take a beating while doing dmg, which is not the case now.
KJC is op when you look at just the ability, but when I look at the whole 3v3 arena game, i don't see how the locks will be good as they are now in 5.3. Even affliction is almost great at the moment, and you can play all 3 specs and all 3 are very much viable.
Locks, for me look like a most balanced class in 5.3, when you look at the big picture, even if they do the channel and hide behind pillar shit that annoys me as a rogue
I'm afraid in 5.4 they will go back to "blah", I hope I am totally wrong
Kinda agree with your points, but even though destro is still viable, I think affli is superior after 10% buff to our dots in 5.3. Destruction is ofc going to take the biggest hit from KJC nerf, but I think destro is in already a little weak state, because they nerfed chaos bolt damage in 5.3. Sustained is ok, but chaos bolt hits only for 50-75k without cd's and since it's got 2,5 sec cast time, I don't find myself getting it off unless we can have cross cc going.
For demo KJC change doesn't actually matter, because demo locks take mannoroth's fury. But mannoroth's fury is also getting same treatment as KJC so I don't think demo locks still exist in 5.4.
I was only talking about affliction, because that is the spec most locks are playing now and with KJC nerfs I think destro would require some buffs (like chaos bolt cast time reduced to 1,75-2 secs and maybe small damage buff?) to be more competitive in 3v3. Nerf to mannoroth's fury will possibly remove demo locks from PvP, because big part of their pressure comes from their aoe abilities.
Of course, anything can still happen and this is just presenting possibilities and views of the current state of locks.